Why Mammograms Are No Panacea

Amy Robach, an ABC correspondent, recently announced on the air that a mammogram broadcast on Good Morning America had found evidence suggesting breast cancer, later confirmed through a biopsy. As a result, she told the audience, she was planning to have a bilateral mastectomy. Several days later, she reported that the surgery had revealed a second tumor and indicated a spread to a lymph node.

Ms. Robach, 40, characterized the mammogram as having saved her life, and news reports about the event included a similar suggestion. That’s not surprising, considering the media’s well-known tendency to exaggerate and sensationalize medical news. Gary Schwitzer, a former health journalist for CNN who now runs the non-profit Health News Review, which analyzes and critiques news coverage of health issues, called the media performance on the Robach story “shallow and incomplete”—an inaccurate portrayal of the risks and choices related to breast cancer detection and treatment.

First off, the program gave few or no details of what exactly the mammogram showed and what the biopsy found about the specific kind of breast cancer confronting Ms. Robach—a crucial factor in any determination of appropriate care and treatment. Moreover, because different types of breast cancer behave very differently—some never grow or spread—it is virtually impossible for Ms. Robach to know whether her mammogram saved her life. As a leading breast cancer expert, Susan Love, M.D., wrote in her blog about the incident, mammography is far from a fool-proof detection method.

“While mammography is capable of finding about 26 percent of cancers at a point where it makes a life-saving difference in the outcome, it also finds many lesions which would never have gone on to be life-threatening,” wrote Dr. Love. “The behavior of the cancer is dictated not so much by when it is found as by what kind it is and how that kind usually behaves.”

These complexities of interpretation are among the reasons that medical panels issuing guidelines for mammograms have differed on whether they are indicated for women between 40 and 50. Many experts believe that the benefits of detecting a tiny number of cancers in that age group do not justify the potential harms and medical costs involved; false positives, for example, can lead to extensive, painful and stressful follow-up care. (Of course, guidelines are designed for population-level decision-making; if a woman under 50 has a family history of breast cancer or other major risk factors, mammograms might well be indicated.)

In contrast, there is general consensus that once a woman passes 50, her chances of getting breast cancer increase enough to reduce the ratio of false positives, rendering mammograms more useful and cost-effective (but not annually; every two years is sufficient). But arguing that mass screening at earlier ages is mostly a waste of precious medical resources and not necessarily indicated for most women under 50 is difficult when public figures like Ms. Robach promote these procedures on television, with little or no mention of any caveats.

In her commentary, Dr. Love wrote that mammograms are a useful tool in making a determination in individual cases, but they are not a panacea; much additional information is required before proper care and treatment strategies can be pursued. “We all need to help tone down the hype that mammograms are the be-all/end-all life-saving tool and stop fueling mass fear that a questionable mammogram is a potential death sentence,” she wrote. While Ms. Robach’s case has ended on a positive note, the publicity surrounding it could prompt a host of younger women to seek out medically unnecessary mammograms.